On Monday, 09/29/2008 at 02:06 EDT, "Schuh, Richard" <[EMAIL PROTECTED]> wrote: > Unless things have changed in the last few years, the VTOC written when > formatting the disk as a CPVOL does not go far enough. If the MVS DASD > Storage Allocation Routine is interrupted while the checking for free > space on the volume, a bit (formerly known as the DADSM Interruption Bit > or DOS VTOC bit, currently known as the VSE bit, name DS4DOSBT in the F4 > DSCB DSECT) is left on. The next time MVS attempts to allocate space on > the volume, it will try to create proper free space records. It does > this buy starting with an F5 DSCB that shows all space available on the > disk. It then runs the F1 and F3 chains, allocating each described > extent. Since there are no allocated extents on a CPVOL formatted disk, > it shows the entire volume as being available for space allocation. > There needs to be at least 1 F1 DSCB allocating the entire volume to a > space-holder dataset to prevent this highly unlikely occurrence.
You need to open a PMR with the ICKDSF team on this if you're interested in getting it fixed (assuming it is still a problem). Alan Altmark z/VM Development IBM Endicott
